#pragma once #include using namespace std; template class IteratorRange { public: IteratorRange(It b, It e) : begin_(b), end_(e), size_(std::distance(b, e)) {} It begin() const { return begin_; } It end() const { return end_; } size_t size() const { return size_; } private: It begin_, end_; size_t size_; }; template class Slicer { public: Slicer(It begin_it, It end_it, size_t page_size) { while (begin_it != end_it) { size_t slice_size = std::min(page_size, static_cast(distance(begin_it, end_it))); pages_.push_back(IteratorRange(begin_it, begin_it + slice_size)); begin_it += slice_size; } } auto begin() { return pages_.begin(); } auto begin() const { return pages_.begin(); } auto end() { return pages_.end(); } auto end() const { return pages_.end(); } size_t size() const { return pages_.size(); } private: std::vector> pages_; }; template auto Slice(C& c, size_t page_size) { return Slicer(c.begin(), c.end(), page_size); }